The present invention is directed to a clear or translucent composition, in gel or stick form, for combatting body malodor, the composition having an antiperspirant active ingredient incorporated therein. The composition of the present invention can be used to combat body malodor, e.g., in axillary regions of the human body, by applying the composition to the human body (for example, to the skin, in axillary regions of the body).
The present invention is particularly directed to clear or translucent antiperspirant compositions in stick or gel form. More particularly, the present invention is directed to a clear or translucent gel or stick composition including a polyamide gelling agent, and having an active ingredient (for example, an antiperspirant active material) incorporated therein, the polyamide gelling agent being stable even in the presence of acidic antiperspirant active materials. The present composition can, preferably, be translucent or clear, but need not be translucent or clear (that is, it can be opaque). Compositions according to the present invention can even be white-opaque as is conventional antiperspirant stick compositions which incorporate, for example, a waxy substance such as stearyl alcohol in the antiperspirant stick.
Antiperspirant products are well known in the art. Antiperspirant products have appeared in the marketplace in various dosage forms, such as sticks, gels, roll-ons, aerosols and creams. Generally, these dosage forms include a solution of the active ingredient in a suitable solvent, a suspension of the active ingredient in a non-solvent, or a multiphasic dispersion or emulsion in which a solution of the active ingredient is dispersed in some continuous phase or in which the solubilized active ingredient constitutes the continuous phase.
The stick form has become a dominant antiperspirant dosage form in the United States market, and is popular to varying degrees globally. Cosmetically acceptable antiperspirant sticks typically consist of a suspension of spray-dried antiperspirant active material in a vehicle such as cyclomethicone, with a waxy substance such as stearyl alcohol, alone or in combination with castor wax, gelling or thickening the suspension sufficiently to create a suitable stick.
The stick form can be distinguished from a gel or a paste in that in a stick, the formulated product can maintain its shape for extended time periods outside the package, the product not losing its shape significantly (allowing for some shrinkage due to solvent evaporation). One can adjust the amount of stearyl alcohol and castor wax and modify the manufacturing process to effect formation of a viscous gel or paste in place of the stick. Alternative gelling or thickening agents such as fumed silica can be used in place of the wax to form the gel or paste. These gels or pastes can be suitably packaged in containers which have the appearance of a stick, but which dispense through apertures on the top surface of the package. These products have been called soft sticks or "smooth-on". Hereinafter, these soft sticks are generically called "gels". Reference is made to U.S. Pat. No. 5,102,656 to Kasat, U.S. Pat. No. 5,069,897 to Orr, and U.S. Pat. No. 4,937,069 to Shin, each of which disclose such gels, including physical characteristics thereof such as viscosity and hardness. The contents of each of these three U.S. patents are incorporated herein by reference in their entirety.
The hard stick dosage form (hereinafter called "sticks"), although widely accepted by the consumer, suffers from leaving a white residue on skin after application, and can cause staining of fabric, which is considered to be undesirable, particularly by female consumers. The gel dosage form can be formulated to eliminate the white residue; however, the product appears initially as white and opaque, requiring consumer education and trial to fully appreciate the low-residue property. Furthermore, in gels of this type, the active ingredient is suspended in a vehicle such as cyclomethicone; in such suspensions, syneresis and creeping of the liquid is a common problem, resulting in instability of the formula or poor aesthetic properties, particularly when shipping product in warm climates and/or at high altitudes.
Recently, there has been significant activity in developing clear and translucent antiperspirant sticks and gels. Clear or translucent antiperspirant sticks consisting essentially of a solution of the active antiperspirant material in a polyhydric alcohol vehicle, gelled by dibenzylidene monosorbitol acetal, have been disclosed. Since the gelling agent is inherently unstable in an acidic environment, and since conventional antiperspirant active materials are acidic, much work has been involved in discovering suitable stabilizing or buffering agents to prevent or slow down acid attack on the acetal gelling agent. Such work has not been completely successful. Moreover, these clear or translucent antiperspirant sticks, containing the acetal gelling agent and including a solubilized antiperspirant active material, have the disadvantage of being inherently tacky. Development work in connection with these clear or translucent antiperspirant sticks, containing the acetal gelling agent, has focused on discovering suitable anti-tack agents for this dosage form. However, since acid hydrolysis of the gelling agent occurs more rapidly in aqueous solutions, formulators have been forced to avoid using water in the formulations. This severely restricts the ability of the formulator to develop cosmetically elegant formulations which are simultaneously chemically stable, optically clear, low in tack, low in residue and which have acceptable application aesthetics.
Clear and translucent antiperspirant gels (which have been dispensed from containers having the appearance of a stick) have been marketed, consisting of viscous, high internal phase emulsions. These gels exhibit some advantages over the aforementioned acetal-based clear sticks, in that the selection of formulation ingredients is less restricted (for example, water can be used), and often tack can be reduced significantly. But these emulsions still suffer from the disadvantages of feeling cool to the skin upon application, and often require the use of ethanol, which has negative environmental regulatory implications.
U.S. Pat. No. 5,500,209, naming as inventors the present inventors and others, discloses a gel or stick which includes active deodorant and/or antiperspirant ingredients, a polyamide gelling agent, and a solvent for the polyamide gelling agent, which gel or stick composition can be clear and/or translucent. The gelling agent is disclosed as forming a continuous phase of the composition, with the deodorant active and/or antiperspirant active ingredient in solution in this continuous phase, or dispersed in this continuous phase, or dissolved in a second, discontinuous phase which is emulsified in the continuous phase (forming a solid emulsion as the composition). This patent application discloses that the polyamide gelling agent is soluble in a cosmetically acceptable solvent at elevated temperatures, and solidifies (gels) upon cooling; acceptable solvents are disclosed as including various alcohols, including various glycols. An illustrative antiperspirant composition described in this aforementioned patent application contains the following:
(a) from 2 to 40 (preferably 6 to 20) weight percent, of the total weight of the composition, of a polyamide gellant, which is defined as a polymer that contains recurring amide groups as an integral part of the main chain; PA1 (b) from 10 to 95 weight percent, preferably 30 to 95 weight percent, of the total weight of the composition, of a solvent for the polyamide gellant (this solvent can also serve as a cosmetic emollient); PA1 (c) from 0 to 50 weight percent, preferably 0 to 25 weight percent, of the total weight of the composition, of a surface active agent to ensure rinsibility of the composition from the skin if the solvent is not sufficiently hydrophilic; PA1 (d) from 4 to 30 weight percent, of the total weight of the composition, of an antiperspirant active ingredient; and PA1 (e) from 0-30 weight percent, of the total weight of the composition, of water.
The contents of U.S. Pat. No. 5,500,209, are incorporated herein by reference in their entirety.
While the polyamide-containing stick or gel disclosed in U.S. Pat No. 5,500,209 contains desirable properties in connection with stability of the composition, particularly in the presence of acidic antiperspirant active materials, and in providing clear or translucent gel or stick compositions, various attributes need to be improved. Specifically, the compositions according to U.S. Pat. No. 5,500,209, containing glycol solvents (e.g., propylene glycol) for the polyamide gelling agent and/or for the antiperspirant active material, have a disadvantageously large amount of tack. In addition, these compositions according to U.S. Pat. No. 5,500,209 containing glycol solvents, must be processed at relatively high temperatures (.for example, around 195.degree. F.).